What Do Sea Birds Eat? (From Krill to Carrion)

Seabirds encompass a diverse group of avian species that predominantly dwell in marine environments and rely on the ocean’s resources for their diet. With keener eyesight and sharper talons, these birds feed on a variety of prey including small fish, squid, shrimp, and krill found beneath the waves. It is intriguing to note that not all seabirds share the same dietary preferences; some may target plankton, while others exclusively dine on crustaceans.

To adapt to their specific nutritional requirements, seabirds have evolved various feeding strategies and physical adaptations. Some species have developed specialized beaks to extract nutritious morsels from the water, while others employ distinct diving techniques to reach greater depths in pursuit of their prey. Apart from their unique feeding behaviors, seabirds also display fascinating migration and nesting patterns, with some traveling thousands of miles in search of abundant food resources.

Key Takeaways

  • Seabirds have diverse diets, including fish, squid, shrimp, and krill, with some species focusing on plankton or crustaceans.
  • Feeding strategies and physical adaptations vary among seabirds, enabling them to thrive in their respective marine environments.
  • Migration and nesting behaviors are influenced by factors such as food availability and environmental conditions, showcasing seabirds’ resilience and adaptability.

General Diet of Seabirds

Seabirds exhibit a diverse range of feeding habits and preferences based on their species and surrounding environment. In this section, we will explore the various types of food that seabirds consume, including fish and other prey, plankton and krill, carrion and waste, as well as aquatic vegetation and mollusks.

Read Next: What Birds Eat Fish?

Fish and Prey

Many seabirds, such as gulls, terns, and puffins, feed on a variety of fish and other marine creatures like squid and shrimp. They rely on their keen eyesight and sharp talons to catch their prey from beneath the waves. Some species, like the gannet, employ diving techniques to capture fish, while others like shearwaters use underwater pursuit to catch their meal. This diversity in feeding methods allows different seabird species to coexist and thrive in their marine habitat.

Plankton and Krill

Not all seabirds focus on larger marine life for sustenance; some primarily feed on plankton and krill. These tiny creatures serve as a significant food source for many seabirds, including albatrosses and petrels. For example, the Cape Petrel uses surface plunging to access these small but essential sources of nutrition. By consuming plankton and krill, seabirds also contribute to the balance of the marine ecosystem.

Carrion and Waste

Seabirds like skuas, gulls, and albatrosses are known to feed on carrion and waste, scavenging on dead marine animals and discarded materials. This diet choice offers various benefits, as it provides a relatively easy and abundant food source. Skuas, for instance, are known to steal food from other seabirds and feed on the remains of their meal. By feeding on carrion and waste, these seabirds play a crucial role in maintaining the cleanliness of the marine environment.

Aquatic Vegetation and Mollusks

Some species of seabirds consume aquatic vegetation, particularly when alternate food sources are scarce. This diet choice enriches the seabirds with essential fiber and nutrients, enhancing their overall health. Additionally, seabirds like oystercatchers and gulls also feed on mollusks, such as clams and mussels. They utilize their strong beaks to crack open shells and access the nutritious meat inside.

Feeding Strategies and Adaptations

Seabirds have developed various feeding strategies and adaptations to efficiently hunt and forage in their marine environment. These strategies often rely on the bird’s specialized physical features, such as talons, bills, beaks, and webbed feet.

Surface Feeding

Many seabirds have mastered the art of foraging at the water’s surface. They are often seen dipping or surface plunging to catch their prey, like terns and red-billed gulls (source). Some seabirds even engage in a behavior called fluttering where they gracefully skim the surface of the water, enabling them to snatch up small fish or crustaceans with their beaks.

Underwater Dive Hunting

Seabirds that excel in underwater dive hunting have unique adaptations that allow them to thrive in aquatic environments. For example, diving petrels and shearwaters use their powerful wings to propel themselves underwater in pursuit of their prey (source). Penguins, on the other hand, have developed strong, flipper-like wings and streamlined bodies that enable them to swim at impressive speeds when hunting for fish and krill. Cormorants and shags use their webbed feet to dive deep into the water and hunt down their prey with their sharp beaks.

Specialized Bills and Beaks

Specialized bills and beaks play a significant role in the feeding strategies of many seabirds. Some birds, such as pelicans, have a large pouch on their lower bill which allows them to scoop up fish from the water (source). Other seabirds, like sandpipers and plovers, have long, slender beaks that are perfect for probing into the sand and mud to find invertebrates.

Major Seabird Groups and Their Diets

Albatrosses and Petrels

Albatrosses and petrels are known for their extraordinary ability to fly long distances. They usually eat a variety of small marine creatures, such as fish, squid, and krill1. These birds are equipped with keen eyesight and sharp talons, allowing them to efficiently snatch up prey from beneath the waves. They also have a special organ called the salt gland, which helps to remove excess salt from their bodies after consuming saltwater prey.

Gulls and Terns

Gulls and terns are adaptable birds that can be found in various coastal and marine environments. Their diet mainly consists of small fish, and they may also eat invertebrates such as mollusks and crustaceans. Gulls are known to be opportunistic feeders, sometimes scavenging from other birds or feeding on human leftovers2. Terns, on the other hand, are more specialized in their feeding habits. They predominantly feed on fish, which they capture by diving into the water from the air, with remarkable precision.


Penguins are flightless birds that can be found in the Southern Hemisphere, particularly in the cold waters of Antarctica3. They are skillful swimmers and divers, using their powerful flippers to propel themselves through the water. Penguins primarily feed on small fish, krill, and squid, which they catch during their deep dives. They have a unique beak structure that allows them to easily grip and swallow their slippery prey while underwater.


Cormorants are large aquatic birds that can be found in both fresh and saltwater environments4. They are powerful swimmers that can dive to impressive depths to catch fish. Their diet predominantly consists of fish, which they catch by pursuing them underwater with their strong, webbed feet. Cormorants also have a hooked beak that helps them grip onto their prey while swimming.

Pelicans and Herons

Pelicans are large birds with a distinctive pouch under their beaks, which they use to catch fish5. They typically feed by scooping up fish with their pouch while swimming or diving from the surface. Herons, on the other hand, are long-legged wading birds with sharp, spear-like beaks that they use to hunt fish, frogs, and aquatic invertebrates in shallow water. Both pelicans and herons are well-adapted to their specific feeding methods, allowing them to efficiently capture and consume their prey.

Environmental and Climate Impacts on Seabird Diets

Pollution and Food Scarcity

The diet of seabirds is heavily impacted by pollution and the resulting food scarcity. One of the most significant forms of pollution affecting seabirds is plastic waste. Seabirds often mistake plastic for food, ingesting it and causing serious health problems. Oil spills also pose a major threat, contaminating their habitat and causing long-lasting damage to their food supply.

In response to food scarcity caused by pollution, seabirds have had to adapt their diets. They feed on a variety of marine life, such as fish and crustaceans. However, with fewer resources available, they may be forced to consume less nutritious prey, affecting their overall health and survival.

Climate Change Effects

Climate change has a major impact on the availability and distribution of the prey that seabirds rely on for sustenance. As ocean temperatures rise, alterations in marine food webs and ocean currents can lead to changes in the prey’s distribution. These changes can reduce the availability of certain prey species and lead to shifts in seabird diets.

Additionally, climate change can cause unpredictable weather patterns, making it more difficult for seabirds to find food. Stronger storms and changing currents may disrupt their foraging habits, forcing them to travel greater distances in search of prey.

Southern Ocean and Antarctica

The Southern Ocean and Antarctica are crucial habitats for many seabird species. However, climate change poses a significant risk to these habitats and, consequently, the diets of seabirds in this region.

Warming waters and melting sea ice in the Southern Ocean can cause a decrease in krill populations, a critical food source for many seabirds. As krill are sensitive to changes in temperature and sea ice conditions, reduced populations of these small crustaceans can have cascading effects on the entire food web.

Antarctic seabirds, such as penguins, depend heavily on krill for their survival. Consequently, the decline in krill population due to climate change can severely impact their diet, causing drastic changes in their foraging habits and negatively affecting their overall health.

Conservation Efforts and Ecosystem Importance

Impact of Overfishing

Overfishing has created significant ripple effects throughout marine ecosystems, especially affecting the prey populations that seabirds rely on for sustenance. As the availability of their food sources decreases, seabirds face a greater challenge to survive and maintain healthy populations. These birds play an essential role in regulating marine ecosystems by controlling prey abundance and transferring nutrients from the ocean to the land through their droppings1.

To combat the negative consequences of overfishing, it’s crucial to prioritize sustainable fishing practices and manage the marine environment responsibly, ensuring that seabirds have access to the food they need to thrive.

Marine and Shorebird Conservation

Organizations like Audubon and NOAA Fisheries have implemented various conservation efforts to help protect seabirds and their habitats23. Audubon’s science-based identification of Important Bird Areas (IBAs) plays a critical role in recognizing and preserving key seabird breeding and foraging sites along the Pacific Coast2.

NOAA Fisheries focuses its efforts on reducing seabird bycatch, which has plagued longline fisheries in Alaska and other regions for years3. By implementing stricter regulations and monitoring, NOAA has mitigated the impact of this issue and significantly reduced the annual number of caught seabirds.

Preserving the delicate balance within our marine ecosystems is vital for the continued survival of seabird populations. Through conservation efforts, we can ensure a healthy and sustainable environment for these birds and the many other species that depend on our oceans’ resources.

Migration and Colonies

Seabirds are unique creatures with fascinating lifestyles. One of their key features is their ability to migrate long distances. These birds are well-adapted to marine environments and are known for their incredible journeys across oceans. A fine example of this amazing migration is the sooty shearwater, which has been observed traveling more than 40,000 miles in a year, crossing the entire Pacific Ocean.

Migration patterns among seabirds can significantly vary depending on the species. However, regardless of the exact distance, migration is essential for these birds to find food and nesting grounds. During this journey, seabirds often display unique behaviors and impressive navigational skills.

Apart from their migratory habits, seabirds are also known for forming colonies when it’s time to nest and reproduce. These colonies are usually situated near water bodies such as rivers and ponds, providing a rich source of food for the seabirds and their chicks. One example of a highly social seabird is the Bank Swallow, which nests in colonies along riverbanks and pond shores.

In these colonies, seabirds make use of vertical banks of dirt or sand to create burrows for nesting, offering protection and optimal conditions for raising their young. These densely populated colonies can be critical to the survival and breeding success of many seabird species.

Frequently Asked Questions

What do albatrosses primarily feed on?

Albatrosses are known for their adaptability when it comes to feeding, but their main diet consists of squid, fish, and other marine organisms. They are able to cover vast distances in search of prey and use their sharp beaks to catch prey in mid-flight or even snatch them from the water’s surface.

How do pelicans catch their prey?

Pelicans are exceptional hunters, using their distinctive beaks and large pouches to scoop up fish from the water. They often hunt in groups, working together to corral fish into shallow waters where they can easily catch them. Once the fish are trapped, pelicans dive in to scoop them up with their pouches and swallow them whole.

What is the main diet for puffins?

Puffins primarily feed on small fish, such as sand eels or herring. They are expert divers, plunging into the water from great heights and using their powerful wings to swim underwater in pursuit of prey. With their strong beaks, puffins are able to catch multiple fish at once and bring them back to feed their chicks or store for later consumption.

Do northern storm petrels eat insects?

Although northern storm petrels are known to eat insects occasionally, their diet mainly consists of plankton and other small marine organisms. They use their keen sense of smell to locate food, and they are agile enough to pick up their prey from the water’s surface while in flight.

What do northern gannets consume?

Northern gannets are expert hunters that primarily feed on fish, such as mackerel, herring, and sardines. They locate their prey from high above the water and dive into the ocean at incredible speeds, using their long, sharp beaks to spear the fish. Once they catch their prey, they swallow it whole, often while still underwater.

Are crustaceans a common food source for seabirds?

Crustaceans, which include shrimp, krill, and crabs, are indeed a common food source for a variety of seabirds. Some species, like terns and seagulls, feed on crustaceans by diving into the water or picking them up from the shoreline. Other birds, like auks and puffins, may feed on crustaceans while diving for fish as well. The availability of crustaceans in a bird’s habitat is a significant factor influencing their diet choices.


  1. https://thebirdidentifier.com/what-do-sea-birds-eat/ 2
  2. https://en.wikipedia.org/wiki/Seabird 2 3
  3. https://abcbirds.org/blog/seabirds/ 2 3
  4. https://teara.govt.nz/en/interactive/5480/seabird-feeding-methods
  5. https://www.allaboutbirds.org/guide/browse/taxonomy/Pelicans

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